Investigation of Thermal Decomposition Behavior of β-Carotene in Air Atmosphere Using Thermogravimetry-Cambridge Filter Trapping

A selfdesigned Cambridge filter trapping device coupled with thermogravimetry/differential thermal analysis (TG/DTA) was introduced and applied to study the pyrolysis mechanism of β-carotene and the dynamic change of relative content of 44 evolved products in each temperature range in air. According to the TG/DTA curve drawed at 10 ℃/min heating rate and 400 mL/min of air flow, main weight loss temperature (MWLT) of β-carotene was gained,which was 200—450 ℃. Then the MWLT was divided into five continuous ranges at the interval of 50 ℃ to study the pyrolysis products of β-carotene after trapping and analysising by gas chromatography-mass spectrometry (GC/MS). Trapping effect of Cambridge filter device was decided by the total peak area of the total ion chromatograms and the percentage of the actual quality loss to total quality in each temperature range. Results showed that trapping effect of the device was much better. Pyrolysis products of β-carotene were mainly produced in the 250—300 ℃ and 300—350 ℃. Some very important scent subtances such as β-Cyclocitral, 5,6,7,7a-tetrahydro-4,4,7a-trimethyl-2(4H)-Benzofuranone, Irisone, 4-(2,2,6-trimethyl-7-oxabicyclo 4.1.0 hept-1-yl)-3-Buten-2-one and so on was founded. The relative content of the 44 evolved products was significantly changed with temperature range.